According to Japanese Laid-Open Patent Publication No. 2003-324901 (hereinafter referred to as “JP 2003-324901 A”), several structures for cooling the inside of the rotary electric machine are disclosed (see FIGS. 1 through 11). In some of the disclosed structures, an oil coolant is supplied radially outward of the rotary electric machine from the inside thereof, such that an oil coolant is circulated through the inside of a shaft 28 (see FIGS. 7 and 8).